Papers by Andrew Stockman
Vision Research, Oct 1, 2018
Proceedings of the National Academy of Sciences of the United States of America, Apr 9, 2018
Journal of Vision, Jun 8, 2007
Vision Research, Jun 1, 2000
Mitochondrion, Sep 1, 2017
Vision Research, Jun 1, 2000
Journal of Vision, Sep 1, 2018
Clinical Ophthalmology, Aug 1, 2016
Journal of Vision, Feb 20, 2018
A precise knowledge of the spectral sensitivities of the human cones is essential for the underst... more A precise knowledge of the spectral sensitivities of the human cones is essential for the understanding and modeling of both normal and defective color vision. Here, we discuss cone spectral sensitivities and their relationship to color matching, and methods of deriving them from psychophysical measurements made in normal, dichromatic, and monochromatic observers. We present a consistent set of mean 2-deg and 10-deg cone fundamentals based on the work of Stockman A. et al. and Stockman A. and Sharpe L. T. Along with the associated lens and macular pigment and photopigment templates, these can be used to model color vision at the cornea and retina and to account for individual differences. Supplemental spectral sensitivities that are of practical importance are the so-called luminous efficiency functions that define spectral lights of equal luminance under rod (scotopic), cone (photopic) and mixed rod and cone (mesopic) illumination levels. Rod spectral sensitivity and scotopic luminous efficiency are identical, and are defined by the Commission Internationale de l’Eclairage (CIE) 1951 V′(λ) function. The photopic CIE 1924 V(λ) luminous efficiency function, though in widespread use, is seriously flawed at short wavelengths. A replacement function, which is also consistent with the Stockman A. and Sharpe L. T. fundamentals, has been proposed by Sharpe L. T. et al.. There is no single mesopic function. Mesopic luminous efficiency is a complicated, non-linear combination of the cone and rod efficiencies that depends on the illumination level and on the measurement task, which has so far proved difficult to define. Both rod and cone spectral sensitivity and luminous efficiency are influenced by large individual differences between observers, including variability in the absorptions in the preretinal optic media. In the cones, further individual differences are introduced by variability in the spectral positions of the underlying photopigments.
Elsevier eBooks, 2010
Effective vision extends over an almost 10 000-million-fold range of light levels, but this extra... more Effective vision extends over an almost 10 000-million-fold range of light levels, but this extraordinary achievement does not come without compromise. First, the range is shared between two different subsystems: the sensitive rod system and the less-sensitive cone system. Second, processes of adaptation regulate sensitivity by trading between improvements in sensitivity at lower light levels, and improvements in spatial and temporal acuity and chromatic sensitivity at higher light levels. Consequently, the processing of spatial, temporal, and chromatic aspects of visual stimuli varies greatly with light level. These changes cannot be captured by spectral luminous efficiency functions alone.
New England Journal of Medicine, 2015
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Papers by Andrew Stockman